Phil Mickelson fist bumps a fan after walking off the 12th hole during the third round of the 113th U.S. Open. / JD Mercer, USA TODAY Sports

by Steve DiMeglio, USA TODAY Sports

by Steve DiMeglio, USA TODAY Sports

ARDMORE, Pa. - Phil Mickelson is in a familiar position once again at the U.S. Open - to either finally close out a win in a tournament he truly cherishes or to suffer yet another maddening close call.

Mickelson, a four-time major champion but the only player to finish runner-up five times in the U.S. Open, shot even-par 70 Saturday in the third round of the U.S. Open at unyielding Merion Golf Club and has a one-shot lead heading into Sunday's final round.

"It's got the makings of something special," Mickelson said of this week. "But I still have to go out and perform and play some of the best golf I've ever played. â?¦ I can't wait to get back out playing. I feel really good about my ball striking, I feel good on the greens, and I think that it's going take an under-par round (Sunday)."

Mickelson leads Hunter Mahan (69), Charl Schwartzel (69) and Steve Stricker (70) by one shot. Another stroke back are Justin Rose (71), Luke Donald (71) and Billy Horschel (72). Jason Day (68) sits three back and Rickie Fowler, who turned in the lowest round of the day with a 67, is four back.

Tiger Woods is 10 back. The world No. 1 hasn't figured out the greens on the East Course, and his third-round 76 knocked him off the leaderboard. World No. 2 Rory McIlroy shot 75 and is nine back.

Mickelson and Mahan will tee off Sunday at 3:20 p.m. in the final round.

Mickelson, who grabbed the rain-delayed first-round lead with a 67 and held a share of the lead after 36 holes at 1 under, fell from the top perch with bogeys on two of his first five holes but rallied with three birdies in his final 13 holes, a stretch whose only flaw was a final-hole bogey. He is the only player under par on this 6,996-yard brute that has had plenty of teeth all week in the form of punishing greens, thin fairways and nasty rough.

Mickelson, who turns 43 on Father's Day, is attempting to win his the U.S. Open for the first time after finishing second in 1999, 2002, 2004, 2006 and 2009. The most excruciating loss came in 2006 at Winged Foot, where he made double bogey on the final hole to lose by one. He summed up the last hole by saying, "I am such an idiot."

This year he has limited his mistakes, doing so without a driver. He loved the course the first time he saw it and likes the feel of this whole week. He flew in overnight on Thursday after his daughter's eighth-grade graduation in San Diego and landed less than three hours before his tee time. Before Saturday's tee time, he said the course was there for the taking.

"It was a day that I thought you could get under (par)," Mickelson said. "And the fact that I was 2 over early, I had to be really patient not to force the issue and fight for a lot of pars out there. And take advantage of a few birdie opportunities.

"I thought that I played better again than the score dictated, but this is a really fun challenge. It is a hard challenge, but it is a lot of fun. Every shot requires such great focus because the penalty can come up and bite you so quickly here.

"It's just a very penalizing golf course. But there are birdie holes out here."

Mahan, one of the best ball-strikers on the PGA Tour, is trying to win his first major title in 30 attempts.

"I feel like my game's been good for a while, and I felt like this course suits me pretty well," he said. "The U.S. Open does. I'm a good ball-striker and you just got to save those big up-and-downs and make those 6- to 8-footers for par, and I felt like I did that today. It feels good to be in the hunt."

Schwartzel, the 2011 Masters champion, is in the hunt for his second major title.

"Obviously it's going to be a tough day, but every day has felt like that," he said. "You're going to have to give every single shot all your attention. There's no hole where you can sort of ease back and sort of freewheel a bit.

"Every shot that you hit is really intense."

Stricker, who has taken some ribbing from players and fans about his new image on a rental car commercial where he says he's a savage, has kept his cool throughout the week and been sharp despite cutting his schedule back this year to spend more time with his family.

He will try to win his first major title in 59 tries.

"I've got to play smart golf," said Stricker, who added that he "felt like a dork" making the commercial but that it was all in good fun. "It's a course where it's tough to come back from. So you have to play smart, you've got to take advantage of some of those shorter holes and give yourself some opportunities. You've got to putt well."

Woods, the favorite coming in, has not been on target with his putter all week. He started the day four shots out of the lead and began with a birdie from 10 feet at the first - then went backward with bogeys at Nos. 3, 5 and 6 as he missed fairways and greens and even chunked a chip. More bogeys would follow, one when he missed a 2-footer.

"It is certainly frustrating because I certainly was feeling like I was playing well this week and I just didn't make the putts I needed to make," Woods said. "The first two days, I had three three-putts and I was four shots off the lead, and I missed a boatload of putts within 10 feet. So I really wasn't that far off. If I clean up the round and don't three-putt, I'm one shot back starting out today.

"I didn't have the speed right this week, and it certainly showed."

McIlroy, who has played with Woods in each of the first three rounds, hasn't fared much better.

"If you're not on your game 100%, you get on the wrong side of the greens and it's just freighting because I didn't feel like I played too badly," McIlroy said. "I missed a few shots here and there, and I was trying on every shot out there and I was trying to get myself back into it, but it's tough.

"If you're just not 100% on top of your game, it's going to expose some of your flaws or weaknesses."